Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Nanoparticles have a relatively large surface area and small volume, causing them to have different properties and different effects than larger materials with the same chemical composition. This high surface-to-volume ratio may make nanoparticles more chemically reactive and more bioactive, potentially leading to medical and/or environmental harm.
Nanoparticles arise in the environment from several sources. Engineered nanoparticles are used in a variety of technologies and consumer products such as cosmetics, sunscreens, textiles, coatings, food and energy technologies, and medical products and medicines. Nanoparticles also arise as byproducts of various systems, for example, from vehicular combustion, particularly by large vehicles with diesel engines.